Pulse mode amplitude modulated (AM) radio transmission of MHz pulse repetition rates by a transmitter, is well known in the prior art. The majority of AM pulse transmitters are not designed for variable MHz frequency bandwidth modulation. Most AM pulse transmitters, whether of fixed or variable carrier frequency, are designed to operate within a very narrow (few tens or hundreds of KHz) modulation frequency range.
A variable pulse rate amplitude modulated transmitter of wide modulation bandwidth is subject to several attributes which are difficult to design. RC and LC charge and discharge constants, as well as circuit reactance can affect the modulation frequency bandwidth and pulse shape. Ideally, wide band width modulation capability will need very short (nanosecond range or shorter) RC and LC time constants. As pulse frequencies, or pulse bandwidth increases, circuit reactance increase, causing significantly diminished output power levels. Increased reactance that occurs with large increases in modulation frequency can cause an imbalance of the output impedance value. It is important to keep the output impedance static (generally 50 ohms) regardless of modulation frequency. A pulse transmitter of fixed carrier frequency that produces maximum output power at 2 KHz modulation frequency may produce very little output power with a 2 MHz modulation frequency. Circuit reactance is a direct function of frequency, a 1000 times change in frequency is accompanied by a 1000 times change in reactance. Large swings in circuit reactance cause unstable output impedances. Stable output impedance is necessary for connection of the transmitter to accessory components such as a power amplifier or an antenna.